Pelvic MRI in spinal cord injury patients: incidence of muscle signal change and early heterotopic ossification.

STUDY DESIGN: Prospective observational study. OBJECTIVE: To evaluate pelvic MRI muscle signal changes and their association with early heterotopic ossification (HO) in patients with spinal cord injuries. SETTING: National Spinal Injuries Unit, Stoke Mandeville, UK. METHODS: Forty patients were imaged with at least two interval magnetic resonance (MR) studies of the pelvis in the first 6 months following a spinal cord injury. Scans were reviewed and scored for heterotopic ossification, muscle signal change and extent of muscle involvement. RESULTS: Muscle signal change was present in 28 (70%) on the initial MRI and 31 (77%) by the second study. Six patients developed MR changes of prodromal or immature heterotopic ossification (15%). No restricted diffusion was demonstrated and no patient developed mature HO. Patients developing MR changes of early HO were more likely to have grade 3 muscle changes. CONCLUSION: Increased T2 muscle signal is common following cord injury, is frequently progressive in the subacute period and is associated with complete injury and early MR signs of heterotopic ossification.

Conus infarction after non-guided transcoccygeal ganglion impar block using particulate steroid for chronic coccydynia.

Introduction: Ganglion impar block (GIB) is a well-recognised treatment for chronic coccydynia. Several side effects have previously been described with this procedure, including transient motor dysfunction, bowel, bladder, and sexual dysfunction, neuritis, rectal perforation, impingement of the sciatic nerve, cauda equina syndrome, and infection. Case presentation: We describe the first report of imaging-documented conus infarction after an unguided-GIB performed in theatre using particulate steroids for a 17-year-old patient with coccydynia. Immediately post-GIB, patient developed transient neurological deficits in her lower limbs of inability to mobilise her legs that lasted for 24 h. These include back and leg pain, decreased power and movement, increased tone, brisk reflexes, reduced light touch sensation and proprioception of legs up to the T10 level. Urgent MRI spine showed intramedullary hyperintense signal within the conus and mild restricted diffusion on the distal cord and conus, suggestive of an acute conus infarction. On follow-up, the GIB did not result in symptom improvement of coccydynia and there was persistent altered sensation of her legs. Discussion: Various approaches of ganglion impar block have been described and performed in the past with different imaging techniques and injectants. A few cases of unusual neurological complications have been reported with the use of epidural steroid injections and ganglion impar block. Clinicians should be aware of the possible neurological complications following ganglion impar blocks and the risk of inadvertent intravascular injection of particulate steroids can potentially to be minimised by using imaging guidance.

Acquired Chiari malformation following spinal cord injury-a case series.

Introduction: Chiari malformation is characterized by caudal descent of the cerebellar tonsils through the foramen magnum. Acquired Chiari malformations (ACM) have previously been described after a variety of pathologies including lumbar puncture, cerebrospinal fluid (CSF) drainage, lumboperitoneal shunts, and conditions causing craniocephalic disproportion. Case presentation: We present four cases of ACM following spinal cord injury (SCI), which has not previously been described in the literature. Discussion: ACM is rare and typically associated with abnormalities in CSF pressure or space-occupying lesions. This case series describes the potential association of SCI with ACM. We discuss the imaging findings and clinical management of these patients. Early recognition and intervention may be important to prevent progressive neurology in this vulnerable patient group.

Non-traumatic myelopathy associated with prolonged hyperextension during swimming: an unusual variation of Surfer's Myelopathy.

INTRODUCTION: Surfer's myelopathy (SM) is a rare cause on non-traumatic acute myelopathy. This has classically been described in novice surfers however has been reported in other scenarios. CASE PRESENTATION: We present a case of non-traumatic paraparesis associated with prolonged cervical hyperextension during swimming with imaging characteristics consistent with an unusual variation of SM in a swimmer. DISCUSSION: SM and its variants should be considered in the differential diagnosis of any patient presenting with an anterior spinal cord syndrome with a history of either sustained or repeated spinal hyperextension.

Polyarticular extension of pigmented villonodular synovitis to contiguous joints via pigmented villonodular tenosynovitis.

Pigmented villonodular synovitis is an uncommon benign neoplastic process that affects synovial-lined joints, bursae and tendon sheaths. We describe polyarticular extension of pigmented villonodular synovitis across joints secondary to pigmented villonodular tenosynovitis. Given that treatment is required to prevent progressive destruction of the involved joint, tendon or bursa, radiologists must be vigilant for diffuse polyarticular or extrasynovial involvement to optimize patient care and initiate appropriate therapy.

Co-existing Paget's disease and ankylosing spondylitis resulting in panthoracic pagetic vertebral ankylosis.

Pagetic vertebral ankylosis is an uncommon presentation and occurs when Paget's disease is associated with diffuse idiopathic skeletal hyperostosis and ankylosing spondylitis. In these cases, the pagetic trait extends from one vertebra to another by invasion of the intervertebral disc space. Such acquired vertebral ankylosis is extremely uncommon but possible when bony bridging syndesmophytes or osteophytes are present. We describe one such case, where a delayed diagnosis resulted in the most extensive pagetic vertebral ankylosis described in the literature and severe patient morbidity.

MRI of aseptic lymphocytic vasculitis-associated lesions in metal-on-metal hip replacements.

OBJECTIVE: The aim of this review is to describe the clinical, histopathologic, and MRI features of aseptic lymphocytic vasculitis-associated lesions in total hip replacements. CONCLUSION: The introduction of modern metal-on-metal hip arthroplasty has been accompanied by a newly described disease, aseptic lymphocytic vasculitis-associated lesions, which is characterized histologically by bland necrosis and dense perivascular lymphocytic infiltrates. Conventional radiographic findings are often normal, but the typical MRI findings include periprosthetic fluid collections, soft-tissue masses, gluteal tendon avulsion, bone loss, periosteal stripping, neurovascular involvement, and periprosthetic fractures. The severity of the histologic and MRI appearances can be graded according to defined published criteria.

Advantages of blood pool contrast agents in MR angiography: a pictorial review.

Gadofosveset trisodium (Ablavar®, formerly Vasovist®) is the first intravascular contrast agent approved for clinical use in peripheral vascular disease. The purpose of this review is to illustrate the clinical uses of gadofosveset-enhanced magnetic resonance angiography in patients referred for assessment of arteriovenous disease. Superior T1 shortening enables first pass renal and peripheral arteriography of quality comparable with larger doses of extracellular agents. In applications such as thoracic outlet syndrome, there may be other advantages such as superior venous imaging and need for only one injection. Steady-state delayed imaging provides high resolution mapping of both arterial and venous systems and imaging of multiple territories. A combination of dynamic and delayed steady-state imaging can provide detailed anatomy and flow characteristics of vascular malformations and mapping for percutaneous sclerotherapy at one investigation. The ability to image in the steady state can provide minimally invasive imaging of thrombo-occlusive disease of central veins.

MR patterns of denervation around the shoulder.

OBJECTIVE: The diagnosis of denervation injury as a cause of shoulder pain is conventionally based on clinical findings and electrophysiologic studies. MRI has an important role in identifying direct and indirect signs of neuropathy and can confirm the presence of nerve compression, depict space-occupying lesions, and exclude other intrinsic lesions of the shoulder. In this article, the relevant anatomy, causes, clinical features, and MR appearances of nerve injury and muscle denervation of the shoulder girdle are presented. CONCLUSION: MRI is commonly performed in patients with shoulder pain of uncertain origin and can determine the morphologic cause, precise location, and duration of nerve injury and muscle denervation. Knowledge of the relevant anatomy, cause, and clinical and imaging findings is important in making a potentially treatable diagnosis, avoiding confusion with inflammatory or neoplastic processes, and obviating biopsy or surgical intervention.